The pattern accepts the following keywords:

• {subdomain}The subdomain which is selected from the Subdomains randomly.
• {level}The zoom level for tiles.
• {x}The column index of the tile.
• {y}The row index of the tile.
• {cx}
• {cy}The latitude of the tile center point.
• {width}The width (in pixels) of the tile image. Always 256.
• {height}